The present invention relates to a new and improved method of optimizing the process of cleaning cotton in a spinning mill with regard to throughput quantity of a carded or card sliver and fiber impairment of the processed product and with regard to residual dirt content in the processed product. The present invention also relates to a new and improved installation for carrying out and performing the inventive method.
In contrast to earlier spinning mills, in which the ring spinning method was the only yarn producing process, new spinning methods have been developed of late in different directive trends, which spinning methods impose different high requirements on the cleaning effect and on the permissible fiber impairment or damage during the cotton cleaning process.
These different requirements could not be optimally met or fulfilled by the hitherto customary cleaning methods with regard to the variability of the throughput quantity, the residual-dirt content and the permissible fiber impairment or with regard to the relationship thereof with respect to one another.
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved method of and installation for optimizing the degree of cleaning cotton and which are not afflicted with the drawbacks and limitations of the prior art methods.
An important further object of the present invention is directed to a new and improved method of optimizing the process of cleaning cotton and, in particular, the degree of cleaning, while taking into account the different high requirements imposed by respective spinning methods with regard to residual-dirt content and permissible fiber impairment. Fiber impairment occurs during fiber cleaning on account of relatively intensive fiber processing and treatment and results primarily in a shortening of the fibers, but also can result in an impairment of the strength and the elongation of the fibers.
Another and more specific object of the present invention aims at providing a new and improved method of and installation for optimizing the degree of cleaning and which take into account the fact that the fibers supplied to a spinning mill represent a blend or mixture of fibers of different provenances or origins, whereby such a blend represents, in turn, an optimization with regard to quality requirements of the finished yarn and with regard to economical requirements with reference to the raw cotton price and the yarn price.
The characteristic features of cotton fibers of different provenances or origins naturally concern the fineness and the length as well as the strength, the elongation and the color of the individual cotton fibers and, depending upon the manner of. the cotton picking- method, the cleanness or contamination of raw cotton.
Such contamination of raw cotton refers to very coarse types of contamination such as metal parts, strings, fabric residues and other foreign elements, but also to coarse parts of cottonseed husks of cottonseed hulls and lately to very fine parts of husks known as xe2x80x9cseedcoat fragmentsxe2x80x9d and which impose high requirements upon the cleaning machines of a spinning mill.
Other types of dirt, which are likewise contained in raw cotton, are the everyday or commonplace dust, dirt from the cotton fields and, to some extent, also the contamination of cotton by honeydew, a sticky or tacky sugar substance which adheres in the form of tiny droplets to the cotton fibers and causes considerable trouble to the spinning mills.
Continuing further, another important object of the present invention is directed to providing a new and improved method of and installation for optimizing the degree of cleaning cotton and which take into account the temperature of the fiber cleaning or processing rooms as well as the moisture content in such rooms and the moisture content in and at the surface of the cotton fibers.
Yet a further significant object of the present invention aims at providing a new and improved method of and installation for optimizing the process of clean cotton and by means of which there is achieved efficient and economical cotton cleaning in a spinning mill optimizing high throughput of the cotton material as required from the standpoint of commercial considerations in conjunction with accurate opening of the cotton bales and careful fiber cleaning as required from the standpoint of technological considerations. The result of such optimization can be quite different depending upon the use of the cleaned cotton fibers in one or the other of the spinning methods.
In order to meet or satisfy the technological requirements, in the first place the opening of the fiber bales should result in fiber flocks of the smallest possible flock size, in the second place the rotational speed of the opening or extraction rollers and the intensity of these opening or extraction rollers in combination with knife elements or carding elements should be such that fiber impairment or damage only occurs to a tolerable extent.
Now in order to implement these and still further objects of the present invention, which will become more readily apparent as the description proceeds, the method of the present development is-manifested, among other things, by the features that,.on the one hand, the fiber characteristics and the proportions of different types of contamination which are inherent to the provenance or origin of the cotton are entered as original or input or given data into control means and that, on the other hand, the desired degree of cleaning and the throughput quantity in m/min of the carded or card sliver are entered into the control means. These control means are programmed such that the control means deliver predetermined control signals based on the entered original or input or given data, the throughput quantity of the carded or card sliver and the entered desired degree of cleaning. Adjustable operating members are set or adjusted by means of these predetermined control signals, such adjustable operating members effecting the rate of opening of respective opening machines, the degree of cleaning. in respective cleaning machines and the rate of processing on at least one carding machine, whereby the adjustable operating members are set or adjusted in such a manner that the desired degree of cleaning and the throughput quantity of the carded or card sliver are achieved, while a presumable fiber impairment of the cotton fibers to be cleaned is indicated or displayed.
A further feature of the inventive method of optimizing the process of cleaning cotton is characterized in that the computed degree of cleaning is checked and monitored during the cleaning operation by means of sensory equipment or sensors located in the waste discharge space of the cleaning machines and, if necessary, automatically corrected.
As alluded to above, the invention is not only concerned with the aforementioned method aspects, but also relates to a new and improved installation for carrying out and performing the inventive method of optimizing the cotton cleaning process.
Generally speaking, the new and improved installation for producing a clean fiber sliver is of the type comprising at least one fiber-bale opener or opening device and a predetermined number of machines for cleaning the fiber flocks or fibers.
In order to implement the aforementioned objects of the present invention, which will become more readily apparent as the description proceeds, the installation constructed according to the invention for producing a cleaned fiber sliver is manifested, among other things, by the features that the fiber-bale opener or opening device and the machines for cleaning fibers are controllably adjustable with respect to the performance and the cleaning effect thereof, such performance being the throughput in weight per unit time such as kg/hr. The installation is further provided with a measuring device for determining the aforesaid performance as well as with a microcomputer control unit for controlling the fiber-bale opener or opening device and the machines for cleaning the fibers such that the fibers are only impaired within a predetermined or specified tolerance.
The advantages achieved by the invention are to be seen essentially in the fact that the cleaning intensity can be adapted to the prevailing requirements, whereby the relations between the cleanness of a carded or card sliver, the fiber impairment and the performance in n/min are in an optimal interrelationship to one another for producing t his carded or card sliver.